A motor was overheating because of low voltage at its terminals. A transformer was installed to correct the problem. What is the secondary voltage of the transformer required to be in order to supply 240 volts to the motor?

240 V

Explanation:

The obvious answer is that if the transformer is connected directly to the motor (with no intervening losses), the output voltage of the transformer must match the required input voltage of the motor, 240 V.

__

We're not given, or asked for any other information, so this is all we can say about the connection. Whether a transformer with a 240 V secondary rating is adequate, we have not enough information to say.